Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
rtc: s35390a: implement nvmem support
This RTC has one "free" register which can be used to store arbitrary
data. Expose it as a nvmem resource in Linux.
Signed-off-by: Lorenz Brun <lorenz@monogon.tech>
Link: https://patch.msgid.link/20251223125728.346073-1-lorenz@monogon.tech
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
authored by
Lorenz Brun
and committed by
Alexandre Belloni
8eeb611b
770a54ac
+32
+32
drivers/rtc/rtc-s35390a.c
+32
drivers/rtc/rtc-s35390a.c
···
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#define S35390A_CMD_TIME1 2
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#define S35390A_CMD_TIME2 3
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#define S35390A_CMD_INT2_REG1 5
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+
#define S35390A_CMD_FREE_REG 7
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#define S35390A_BYTE_YEAR 0
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#define S35390A_BYTE_MONTH 1
···
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.ioctl = s35390a_rtc_ioctl,
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};
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static int s35390a_nvmem_read(void *priv, unsigned int offset, void *val,
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size_t bytes)
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{
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struct s35390a *s35390a = priv;
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+
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/* The offset is ignored because the NVMEM region is only 1 byte */
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return s35390a_get_reg(s35390a, S35390A_CMD_FREE_REG, val, bytes);
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}
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static int s35390a_nvmem_write(void *priv, unsigned int offset, void *val,
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size_t bytes)
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{
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struct s35390a *s35390a = priv;
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return s35390a_set_reg(s35390a, S35390A_CMD_FREE_REG, val, bytes);
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}
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static int s35390a_probe(struct i2c_client *client)
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{
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int err, err_read;
···
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struct rtc_device *rtc;
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u8 buf, status1;
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struct device *dev = &client->dev;
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struct nvmem_config nvmem_cfg = {
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.name = "s35390a_nvram",
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.type = NVMEM_TYPE_BATTERY_BACKED,
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.word_size = 1,
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.stride = 1,
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.size = 1,
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.reg_read = s35390a_nvmem_read,
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.reg_write = s35390a_nvmem_write,
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};
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if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
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return -ENODEV;
···
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if (status1 & S35390A_FLAG_INT2)
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rtc_update_irq(rtc, 1, RTC_AF);
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+
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nvmem_cfg.priv = s35390a;
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err = devm_rtc_nvmem_register(rtc, &nvmem_cfg);
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if (err)
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return err;
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return devm_rtc_register_device(rtc);
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}